This release is more than a memento of Gyorgy Kurtag’s 80th birthday concerts, featuring works not yet recorded commercially. Of these, …concertante… is the latest of the large-scale works running across the latter half of his career – violin and viola are the closely intertwined soloists in music that allies a process of continual development with the formal markers of sonata form, culminating in a fateful apotheosis of the kind Kurt·g has made his own.

The composer felt sufficiently indebted to Hiromi Kikuchi to write a work especially for her. Hipartita is no cursory “thank you”: its density of thought evident in the gravity of the opening “Sostenuto”, the inexorable tread of “Oreibasia” and sombreness of “Teneramente”; with the momentum of “Perpetuum mobile” carrying over into “Heimweh” for a raptly inward epilogue. The whole piece is supremely realised by Kikuchi.

The other works exude a lower level of intensity without being less characteristic. Zwiegesprach is an evolving collaboration between father and son, in which the evocative contribution of string quartet is occasionally swamped by synthesiser. The programme concludes with the selection of Jatekok and Bach transcriptions that Kurtag and his wife have toured in recent years. However, the performance – on an upright piano with the mute pedal permanently depressed – is more the enactment of a ritual than one emphasising musical concerns.

Those wishing to hear the Kurtags in a wider range of these pieces should turn to their ECM recital. Otherwise, these discs warrant the highest recommendation – capturing the spontaneity of the music-making to a degree only possible with live performances.